1. Field of the Invention
The present invention relates to refrigerators, more particularly to refrigerators having product storage and dispensing, and more specifically to an ice dispenser for a refrigerator.
2. Description of the Related Art
A refrigerator is a large container that is usually powered by electricity to be kept cool inside so that food and drinks in it stay fresh. In recent years, through-the-door ice and beverage dispensers have been developed for refrigerators that can provide a user with a beverage and pieces of ice without opening a door of the refrigerator. In addition to convenience, this has the benefit that cool air is prevented from leaking out of the refrigerator.
In one conventional through-the-door ice dispenser, an ice reservoir in which an ice supplier is mounted is disposed inside a refrigerator. Defined on a front side of a refrigerator door is a cavity for receiving a cup. The ice reservoir communicates with the cavity through an ice supply tube so that pieces of ice can be supplied to the cup from the ice reservoir through the ice supply tube.
Fixedly mounted on a top surface of the cavity is a bracket to which a damper door for opening/closing the ice supply tube is pivotally connected. An elastic member is supported on the bracket to bias the damper door toward an ice supply tube closing position when the dispenser is not operating.
The dispenser further comprises a first lever having a first end disposed on one side of the damper door and a second end pivotally coupled to an inner wall of the cavity, and a second lever integrally branched off and extended downward from the first lever. That is, the second lever is disposed such that as the cup is inserted into the cavity it is moved inward so that the first lever pivots to open the ice supply tube while overcoming biasing force of the elastic member.
Meanwhile, a switch for operating the ice supplier is mounted inside the door, the switch being operated by the second lever. That is, the switch is turned ON while the second lever is pushed by the cup toward the inner wall of the cavity to operate the ice supplier, thereby dispensing pieces of ice from the ice reservoir to the cup through the ice supplying tube.
When the cup is withdrawn out of the cavity after being supplied with pieces of ice, the switch is turned OFF so that the operation of the ice supplier is stopped, and at the same time, the damper door is returned toward its closed position by biasing force of the elastic member, thereby closing the ice supply tube. At this point, if the damper door abruptly closes the ice supply tube, many pieces of ice which are being supplied through the ice supply tube may remain within the ice supply tube. To solve this problem, a retarder is provided facing the damper door for retarding the return of the damper door to the closed position. The retarder includes a retarder housing defined by a portion of the inner wall of the cavity, a piston slidably disposed in the retarder housing, and a rod coupled at its one end to the first lever and at the other end to the piston. The rod is drawn out of the retarder when the damper door is opened, and when the damper door is closed, the rod is inserted into the retarder housing by biasing force of the elastic member. At this point, the damping force of the retarder retards the return of the damping door to the closed position.
However, in the above described conventional ice dispenser, since the damping force of the retarder changes over time, in particular lessening over the life of the device, the retardation time during the return of the damping door to the closed position is shortened, causing the ice supplying tube to be too quickly closed. As a result of this, pieces of ice may be caught at an outlet of the ice supply tube by the damper door or remain within the ice supply tube, lowering the reliability of the dispenser.
Other examples of the conventional art are seen, for example, in the following U.S. patents. U.S. Pat. No. 3,537,132, to Alvarez, entitled Household Refrigerator With Through-The-Door Ice Service, describes a ice dispenser with a time delay to keep a trap door open for a few seconds after discharging the ice. The illustrated time delay mechanism is a dash pot, and such a device can undergo the loss of reliability with time described above.
U.S. Pat. No. 3,942,334 to Pink, entitled Door Delay Closing Mechanism For The Ice Chute From A Power Driven Ice Dispenser In A Freezer-Refrigerator, describes a spring-loaded door of the ice chute of a freezer-refrigerator with a delay mechanism to prevent ice from remaining in the chute. The mechanism uses a mechanical inertia motor to delay the door closing. Such a mechanical device may undergo loss of reliability with use over time.
U.S. Pat. No. 4,069,545 to Holet et al., entitled Door Control Device With Closure Regulator, discloses a device for slowing the closure of a door of an automatic ice maker. The door is clutched to a rotor positioned within a stator. The stator contains a fixed volume compartment with a viscous fluid, and the fluid impedes rotation of the rotor. Such a device may be subject to loss of reliability over time.
U.S. Pat. No. 4,090,641, to Lindenschmidt, entitled Refrigerator Ice Door Mechanism, describes an ice chute door with a conventional time delay means to delay the closing of the door. This means is a mechanical delay device which is cocked when the door is opened. As described above, such a mechanical device is subject to loss of reliability.
U.S. Pat. No. 4,220,266 to Braden et al., entitled Ice Door Delay Mechanism, describes a delay mechanism including a suction cup which attaches to a planar surface to hold the ice door open. An air-bleed mechanism provides a delay until sufficient air has entered the suction cup for suction to be lost.
U.S. Pat. No. 4,462,337, to Prada, entitled Door Control Device With Closure Regulator, discloses a device for slowing and impeding the closing movement of an ice dispenser door. The device includes a sealed flexible container containing a viscous fluid and rollers engaging the container. Deformation of the container by the rollers is slowed by the viscous fluid to provide the slowing mechanism.
U.S. Pat. No. 5,279,445, to Fisher, entitled Cable Operated Ice Dispensing Door, describes the door mechanism of an ice chute for a convenience store beverage dispenser. The door is operated by a solenoid operating a piston which moves a link and lug to lift or lower a plate and the door. Alternatively, the solenoid may operate a piston which moves a cable through a pulley system to operate the door. This invention was an attempt to solve the problem of premature wear on solenoids in link-operated doors due to the lateral stress on the solenoids, and the problem of providing the pull strength necessary to directly operate the door. The device requires a solenoid of sufficient power to open the door. Moreover, this invention deals with preventing ice spillage, that is, continued flow of ice after the receiving cup is pulled away. Thus, the invention does not deal with the delay in door closing desired in the through-the-door ice dispenser.
U.S. Pat. No. 5,860,564, to Jablonski, entitled Ice Dispensing Chute, describes an ice dispensing chute mechanism for an ice dispensing machine, in which a solenoid drives a rod to open and close a door on the ice bin. In this mechanism the door retains the ice in the bin. As above, this invention requires a solenoid of sufficient power to open the door, and does not deal with a mechanism for delaying the closing of the door after a switch is released, as is desirable for the refrigerator in-door dispenser.
U.S. Pat. No. 5,526,854, to Unger, entitled Through The Door Water And Ice Dispenser, discloses a door for an ice chute of a through-the-door dispenser. In this patent, a dispenser comprises a damper door for opening/closing an ice supply tube and an actuator for pivoting the damper door between a closed position and an opened position. The actuator includes a piston and a spring biasing the piston. Mounted between the damper door and the actuator is an arm coupled at its one end to the damper door to pivot about a pivot shaft together with the damper door and at the other end to the piston of the actuator. In more detail, when a cup is inserted into a cavity to turn a switch ON, thereby the actuator being electrically energized, fluid within the actuator is caused to vaporize and extend the piston against the internal spring. When withdrawing the cup out of the cavity, thereby the actuator being de-energized, the vapor commences to cool, and after a delay, the internal spring moves the piston back to its retracted position causing the damper door to return to its closed position. Since there is a delay in the closing operation after the dispenser is de-actuated, sufficient time is allowed to permit all pieces of ice to be exhausted out of the ice supply tube.
However, in the Unger dispenser, to maintain the damper door in an opened state, electric power is continually applied to the actuator and a relatively large amount of operating force of the actuator is required to completely open and close the damper door, thereby increasing electric power consumption. In addition, to allow the damper door to tightly contact an outlet of the ice supply tube when the damper door is closed, since a spring having a high elastic coefficient is required, the capacity of the actuator has to be large to operate the piston against the spring having the high elastic coefficient.
Based on our reading of the art, then, we have decided that what is needed is an ice chute of a through-the-door refrigerator with a delayed damper door closing mechanism which does not lose its reliability over time, as do many mechanical delay devices. Our reading of the art indicates that electrical actuators which directly operate the damper door are subject to wear and reliability problems, and in addition consume excessive electrical power. What is needed then is a mechanism which does not suffer from these deficiencies.